QST de W1AW
Propagation Forecast Bulletin 33 ARLP033
From Tad Cook, K7VVV
Seattle, WA August 9, 2002
To all radio amateurs
SB PROP ARL ARLP033
ARLP033 Propagation de K7VVV
After the previous week's heightened activity, solar flux and sunspot values rolled back quite a bit. Average daily sunspot numbers for this week were down 120 points, and average daily solar flux was off nearly 70 points. Solar flux values fell since reaching 241.5 on July 16 but should rise again next week. Solar flux values predicted for August 10-16 are 135, 140, 145, 145, 150, 150 and 160. Solar flux is expected to peak in the vicinity of 215 around August 23-24, based on the previous solar rotation.
Geomagnetic conditions should be quiet for the next few days, but it sure wasn't quiet August 1-3, when planetary K indices reached 6, indicating a geomagnetic storm complete with dramatic aurora displays at northern latitudes. Check out the link to the Auroral Station in Adventdalen Web site in Norway. Also check the Aurora Links page of the University of Alaska for more aurora information as well as the NOAA Today's Space Weather and SpaceWeather.com sites for daily space weather updates.
Day by day we will gradually move away from summertime to fall propagation. We will especially notice a change on 10, 12 and 15 meters, which are affected by thinning of the ionosphere during the summer. K3MIY mentioned in an e-mail this week that ionospheric heating in the northern hemisphere causes this. The most reliable DX band right now is 20 meters.
K9GY requested a plug for the CW portion of the Worked All Europe DX Contest this weekend. He mentioned http://www.waedc.de/ for more info on the contest. For path projections, those interested in working Europe might use a solar flux value around 140 plugged into the W6ELprop software, which you can download from the W6ELprop site. W6EL recently updated the software to version 2.61, making some improvements to the user interface.
Sunspot numbers for August 1 through 7 were 259, 220, 218, 150, 144, 135 and 141, with a mean of 181. The 10.7-cm flux was 192.6, 180.3, 167.8, 150.9, 141.9, 144.6 and 136.2, with a mean of 159.2. Estimated planetary A indices were 26, 37, 20, 16, 8, 9 and 8, with a mean of 17.7.